Engineers are working to fix the issue that has meant customers can not use their mobile data to access the internet and other services on its network. O2 says technical teams are working "extremely hard to resolve this".

Outages were reported across the United Kingdom, including Manchester, London and Exeter.

The mobile phone provider said: 'One of our 3rd party suppliers has identified a software issue in their system.

The company has confirmed that voice calls are still working, and have asked customer to alert them to any network issues they may be experiencing.

An O2 spokesperson said the network was continuing to investigate the problems.

"We'd encourage our customers to use Wifi wherever they can and we apologise for the inconvenience caused".

It's encouraging users to "use Wi-Fi wherever they can".

The problems are UK-wide and O2's Twitter account spent the morning engaging with customers who were having issues with data.

In addition, London Bus timetables rely on O2's coverage, meaning that these were also down this morning.

The company, the second-largest mobile network in the United Kingdom, said it was investigating the technical fault.

TFL said: "The company that updates the data to our network of Countdown Systems is now experiencing difficulties in providing this service".

It is not clear when the issue will be resolved, but O2 said it would share further updates as soon as possible. "This issue is being investigated".

However, many people reported difficulties in accessing the service status page itself.